Pump check valve



Nov. 6, 1956 H. l.. MlscH PUMP CHECK VALVE:

Filed Oct. 28, 1952 nina .PZOML .Suma

/1 TTORNEYl United States Patent LO PUNIP CHECK VALVE Herbert L. Misch,Royal Oak, Mich., assignor to Studebaker-Packard Corporation, acorporation of Michigan Application October 2S, 1952, Serial No. 317,285

5 Claims. (Cl. 137-512) This invention relates to uid handling means andmore particularly to hydraulic valve means for use in the control systemof an automatic transmission device or the like.

Several of the conventional automatic transmission means now used onautomobiles make use of a dual pump system that cooperates with ahydraulic control mechanism. ln such systems, one pump is driven by theinput to the transmission of the car and another pump is driven by thetail shaft or output from the transmission. These two pumps are usuallydesigned to have diterent operating characteristics so that when theautomobile is moving slowly as in starting up, the input driven or frontpump, will supply a relatively large volume of fluid to render thecontrols operative. The rear or tailshaft driven pump is somewhatsmaller than the front pump, but it is designed to operate at a higherspeed and pressure to produce a sufficient volume of output to overridethe front pump and maintain the proper functioning of the controlsduring normal driving. This dual pump system thus provides two pumpshaving different characteristics so that the pump can be energized whichoperates more efiiciently for'the particular driving conditionsprevailing at any given time. The system also makes it possible to soarrange the hydraulic controls that under unusual conditions, the rearpump may be driven by the driving wheels of the car to actuate thecontrols and driving gear in order that, if necessary, the car may bepushed to turn the motor over in an attempt to start it.

In one type of such a transmission, in order to automatically render thefront and rear pumps alternatively operative depending uponpredetermined conditions, the output of each pump is delivered to acommon valve casing having suitable check valve means therein. rIhevalve functions in a manner to permit a fluid ow to take place into theautomatic control system from the pump that is then pumping hydraulicfluid at the highest pressure. This invention is concerned with thischeck valve means and provides an improved valve for cooperating betweenthe pumps to effect proper delivery of the pressure uid to the controlsystem.

VThe improved structure provides a very light weight spring form ofcheck valve means which is substantially instantaneously responsive tothe front and rear pump pressures. Further, the check valve means isdesigned to cooperate with the hydraulic uid and the valve casing so asto be quite silent in operation.

The preferred form of this invention is shown in the drawing wherein,

Fig. l is a diagrammatic representation of a typical hydraulic controlsystem wherein the check valve means of this invention might be used;

Fig. 2 is a cross sectional view of a valve casing with the check valvemeans of this invention positioned therein; and

Fig. 3 is a perspective view of one of the check valve means.

Referring to Fig. 1, there is shown the front pump that ICC 2 is adaptedto be driven by any suitable means from the crankshaft of the engine ofthe automobile. 'I'he pump 10 is operative at relatively slow speeds, aswhen starting up, to deliver a sufficient volume of uid through itsoutlet 11 to supply a torque converter 12 with pressure uid and to alsoenergize the various valve means of the control system which aredesigned to eect automatic operation or the several servo motors forcontrolling the application of the engine torque to the drivingwheels.As the speed of the automobile builds up, a rear pump 13 which is drivenby the output shaft from the automatic transmission, and which isresponsive to the speed of rota.- tion of the rear wheels, also deliversa supply of uid into its output conduit 14. f

In the form of automatic transmission here shown, the front pump 10 isdesigned to operate at relatively .low speeds to deliver a sutiicientvolume of uid to ll the automatic control system and maintain asufficiently large volume of ow through the torque converter to keep theconverter cool as the converter is used to drive the car. The rear pump13 on the other hand, operates at relatively higher speeds at which timethe power flow through the torque converter may be by-passed by theengagement of a direct drive friction clutch 15 so that a smaller volumeof fluid flow will sutce. Further, as the speed of the automobile buildsup, a smaller pump may be operated at a higher speed to more eicientlydeliver a proper volume of uid at the optimum pressure to operate thesystem. To meet these conditions of operation, the larger front pump 10is provided with a pressure relief valve 16 which permits the fluid owfrom pump 10 to reach a steady upper pressure and thereafter anyexcessive uid from the pump 10 is by-passed. With such an arrangement,when the rear pump 13 is driven to operate at a higher pressure as isusually the case, during normal operation above a certain preselectedspeed and except when starting up or driving in reverse, the rear pump13 is operative to supply all of the Huid to the Control system andtorque converter while front pump 10 runs idly.

The check valve means of this invention is provided to accomplish theconnection of either the front or rear pump to the hydraulic systemdepending upon whichever pump generates the higher pressure and providesautomatic control means for delivering the higher pressure fluid fromone or the other of these pumps into the circuit.

For this purpose the output iiow from the front pump and the output owfrom the rear pump are delivered into opposite ends respectively of thecheck valve casing 26, the front pump inlet 21 feeding the uid into oneend thereof and the uid under rear pump pressure being delivered intothe valve casing through the inlet 22. The casing 20 is provided withone or more outlet openings such as 23 and 24 which communicate with thehydraulic system and through which fluid under pump pres.- sure issupplied to the valves and torque converter. The various valve controlmeans and their connections are disclosed in the following copendingapplications and form no part of the present invention which isconcerned only with the structure of the check valve means for electingselective delivery of front or rear pump pressure uid to the controls:71,128, McFarland, January 15, 1950 now Patent Number 2,694,948 issuedNovember 23, 1954.

148,022, Lucia, March 7, 1950 now Patent Number 2,693,260 issuedNovember 11, 1954.

171,690, McFarland, July 1, 1950 now Patent Number 2,689,029 issuedSeptember 14, 1954.

172,659, McFarland, July 8, 1950 now Patent Number 2,693,810 issuedNovember 9, 1954.

173,789, McFarland, July 14, 1950.

2,691,940 issued October 1-9, 1954.

118,975+ McFarland, August 11, 195i) now Patent Num-Y 2,118,427 issued;December 1795-5.

y arcanes Th' iiiipr'oved'Z check valve'meansof th-is invention is valvecasing 20 and the check vallves',r alsri`s best-s'en-dinfFig'. 2, aresituated to' cooperate witlrvalveseats located between the inlet Z'Ia'ndthe outlet' 23'Y andbretween the inlet 22 and outlet 24.

.The check valve rieansofV this invention, preferably takes theform of agenerallyA U shaped lea-f 2Sv adapted to bevdispos'ed in the valvecasingr2) adjacent the iniet 21 andan identical` U shaped leaf 26disposed in casing' 2t,"

. adjacent inlet 22: `Valve 25 is adapted to coopera-te witn Y a seat 27and Yvalver26 cooperates with a seat '23, the

seats" 21 and Y28l preferably being formedY by cutting slots iriV the'valve-casing 20 which slotsV have parallel sides that intersect thefluid passage 30 at approximately right angles, whichpassage connectsthe valve casing inlets 21 'and 22. Y

Each of the U shaped leaf members 25 and 263 may be Y formed Vto ,anidentical patternand each valve element has a at face 35 which isadapted to bear against Ythe valveV seats 27 and 28. vArm' 36 of the Ushaped leaf valve ,means is formed to Yhave a non-planar surface so thatit cannot close oli" the face of the slot 29 opposite,

t'o the valve seats 27 or 28'for a purpose that will appear moire' fullybelow. The body of the leaf valve is designed vto' have just suicientwidth to be slipped Vinto slot 29 while having' alittle play withVrespect to the sides of the slot so that the valve surface 35 may moveaway from its cooperating seat to open whenthe pressure builds up. Whenyeither ofy thevalvcs opens, fluid may ow from the inlet adjacentthereto, into the passage 30 and then out theV outletlmeans leading fromthe casing.

I In the operation of this mechanism, when the engin of the automobileis started up, the front pump begins to rotate and Athe Yvolume andpressure of the uid flowing therefrcuriV builds up. K As the motor isspeeded up, a 'suicient 'qut'ultityA of iluid is yquickly supplied fromthe Y relatively large volume front pump which iiuiclV iillsV theconverter :and vall of the conduits of the control system.

lthe automobile remains stationary with the .enginerunning-,all of theluidY delivered from the Vfront pumpjpasses through conduit 11 and aportion of Vits pres e *sure is eXertedV against the Yface of the leafvalve 25 to open the` valve so that pressure Yiluid flows intotheconduit Siland against the -rear of valver26. Since there isilo pressurebeing -generated by the motionless rear 13, the valve 26 Vremains closedand the front pump supplies pressure iiuidrthroughrihe outlet conduits Y23 and-24 from `the valve casing V2t) to llthesystem and furnish fluidto the torque converter. l

lVYVhei thefen'gine of the :automobile is speeded up and thecar beginsVto vmove therear pump 13 is driven vand iiiuid Vr'n'xirlr'rrlllgradually 'builds up lto be 'delivered throughconduit 14 against theface of Vvalve 26.-'The valve 26 however Vremains closed until Vthepressure from therear pump 13 is greater than the pressure developedtions, resulting lfrom the4 sim.ultaneousr operaii911A Qi,

front and rear pumps.

In practice,rth'e front pump Vis usually provided witha Y pressurerelief 'valve Yas explained above so that this relatively larger pumpneed not be operated in a mannerV toV Y supply excessive fluid When/theVautomobile is in normal motion thereby saving considerable energy. Thecheck valve system here disclosed-'thus cooperates with this front pumppressure reliefmeans to insure the Vrapidi and positive takeoverof'ptheiiuid,,pumpingfunctionfby the rear pump 13 as soon asthe hydraulicpressurefromthe rear pump builds up. f Y Y In the unusual instance wherethe motor of the automobile may be hard to startand it is desired topush Vthe car to turn over the engine, it is apparent that the frontpump 10 will remain stationary while the rear pmnp 13 is driven byrotation of the rear Vwheels of the car when itis pushed.V While thefront pump remains inactive,V Y

pressure Vis delivered from the rear pump 13. through'conduit 14 toinlet 22 and as there isrno front pumppressure in conduit V30 at thistime,'the valve 26 will open and pressure iluid will flow intoconduit 30from( inlet` 22.

The valve 25 will remain closed Ybecause of the rear pump Y pressureexerted against its backside,` however, 'although somewhat inefficient,pump 13 will in this manner supply a ilow of pressure uid to thehydraulic controlsystem and converter so that the engine can beturnedover in an attempt to start it by means of pushing the car.

' `Refefrringto Fig. 2, it will be seen that valve casing 20 has a thirdoutlet passage 4t) formed therein which communicates directly with inlet22 in front of the check valve 26. Outletrli)` leads to conduitV 41,showndiaf Y grammatically in Fig. 1, adjacent pump 13,to supply pressureiluid to the governor and the valve associated therewith, theoperationvof which` will appearrmore Vfull),l

Serial No.V 172,659 j in the aforementioned application, now Patent No.2,693,810. Y

The above description covers the preferred form and operation ofthis'invention.4 It will be apparent to those skilled inV the art thatmodicationsthereof may be made which .will fall within the scope vof thefollowing claims.

I claim:

1Q A valve devic'excomprising a housing having two Yspaced apart inletscommunicating with the interior thereof, loutlet means communicatingwith said interior, said 'Y outlet means comprising a pair of spacedVapart annular Y slots formed about said interior between the spacedinlets, Y.

a VU-shaped valvemember seated in each slot, said valve v member beingformedV of resilient material and khaving `against the rear side thereofby thev front pump V10.V AsV Y Vsoonas thefpressure in conduit4rand.in`let 22 of the valve casing builds Yup toY a degree higher thanthe pres- '65 sure prevailing in 'conduit 30, the valve 26 opens andinlet from-'the outlet and abow shapedf'side engaging 'in .Y `V partwith the Yotherside of sai'd'slot for.permitting-conlVtinuousYcnnrnunication between theradjoining portion of Vthe interiorof thehousing and the outlet.y 'Y 'Y 'Y the opposite sides thereofbiased awayrfrom Veach otherVY into 'engaging relation with theYY sidesofY the associated` slot, said Vvalve Vmembercomprising one at sideseated against the sideof the slot adjacent theY associated; linlet forselectively sealing' saidV inlet froml Vthe'outletV and `aYV bow shapedside Vengaging'fin part with the other-iside of said slot forpermittingcontinuous communication ,.be-V

tween the adjoining portionof'thej interior of the h'ous ing and theoutlet. Y I Y 2. A valve device comprisingia housinghaving twoiispacedapart inlets communicating with the interior,therev-V Y of, outletmeansfor said housing comprising a pair of spaced apart annular,slots'formedabout saidV interior between the. spaced inletsfa resilientU-shaped Vvalve member seated in each Vslot with theopposite-rsidesthere.-

of Vbiased away from Veach-other into .engagin'grelation with the sidesof the associated'slot, Vsaidvalvelrnember comprising one atfsideseated'against the side ofgthe slot adjacent its associated iuletgforselectively sealingxsraid 3. A valve. device Vcomprising' a housinghaving two Y spaced apart inlets communicating with the interior-there--of, anV outlet communicatingfwith thelinterior of sid Y housingandfincluding aslo't termed annularlyfabout the Y.

inner surface of said housing, a U-shaped resilient valve member Ihavingthe sides thereof biased into engaging relation with the sides of saidslot, said valve member comprising one at side adapted to seat againstone side of said slot for interrupting the communicating relation fromone inlet to the outlet and a bow shaped side partially engaging withsaid other side of said slot for permitting continuous communicationbetween the other inlet and the outlet.

4. A valve device comprising a housing having at least one inlet and anoutlet communicating with the interior thereof, said outlet including aslot formed annularly about the inner surface of said housing so that aportion of said inner surface is on the inlet side of said slot andanother portion of said surface is beyond said slot, a U-shaped valvemember seated in said slot and comprising one at portion adapted to seatagainst one side of said slot and a bow shaped portion engaging in partwith said other side of said slot whereby the at portion of the valvecan interrupt the communicating relation with the outlet and the bowshaped portion can permit continuous communicating relation between theoutlet and the portion of the interior of the housing beyond the slot.

5. A valve device comprising a housing having two spaced apart inletsand an outlet communicating with the interior thereof, said outletincluding a slot formed annularly about the inner surface of saidhousing, a U-shaped valve member seated in said slot and comprising oneat portion seated against one side of said slot and a bow shaped portionengaging in part with said other side of said slot whereby the atportion of the valve can interrupt the communicating relation from oneinlet to the outlet and the bow shaped portion can permit continuouscommunicating relation from the other inlet to the outlet.

References Cited in the file of this patent UNITED STATES PATENTS303,702 Carricaburu Aug. 19, 1884 310,935 Fell Jan. 20, 1885 978,152Gutermuth Dec. 13, 1910 1,229,457 Hildebrand June 12, 1917 1,594,168Goff July 27, 1926 1,697,004 Gutermuth Jan. 1, 1929 1,791,449 KennedyFeb. 3, 1931 1,938,369 Beebe Dec. 5, 1933 2,065,062 Dugelay Dec. 22,1936 2,599,499 Thorstenson June 3, 1952 FOREIGN PATENTS 9,764 GreatBritain 1913 18,175 Great Britain 1906 488,924 Great Britain Iuly 12,1938

